Base for electric lamp



i April '29, 1969 c. vrat-:lss

ABASE FORv ELECTRIC LAMP Filed June 25, 1966 FIG.5

INVENTOR, CLUUE DEISS awa United States Patent 3,441,778 BASE FOR ELECTRIC LAMP Claude Deiss, Paris, France, assigner to Fabrques Reunies de Lampes Electriques, Camille Desmoulius, Issyles-Moulneau, Hauts-de-Seine, France Filed June 23, 1966, Ser. No. 559,815 Claims priority, applicgtionlFrance, .lune 23, 1965,

Inf. Cl. Hoij 5/48, 5/50 U.S. Cl. 313-318 4 Claims ABSTRACT 0F THE DISCLOSURE This invention relates to electric incandescant lamps or discharge lamps having at least one seal in the form of a pinch. This seal has one or more peripheral'parts which are usually parallel and equally directed with the axis of the lamp and on which current-supply members of metal sheet are clamped; each peripheral part is also connected in an electrically-conductive manner to a current-supply wire emerging from the pinch.

If this shape of lamp is used for electric incandescent lamps which are highly loaded, such as halogene lamps or discharge lamps, use is frequently made of bulbs of quartz glass or similar refractory material because of the high operating temperature. These known lamps often utilize current-supply members of :thin material which are clamped in position on the pinch and substantially surround it.

An object of the invention is to provide an improved design of such current-supply members. To this end, the lamp of the kind referred to according to the invention is characterized in that each current-supply member is clamped, by means of an approximately U-shaped profile on one of the preferably thickened peripheral parts of the pinch and extends substantially at the side of this pinch.

The use of the invention affords several advantages. In the first place the pinch can radiate its heat freely since radiation is not rendered by the presence of a currentsupply member over a considerable portion of its surface. Furthermore the portions of the current-supply member which are located at Athe sides of the pinch fulfill the function of cooling iins which are exposed to the ambient atmosphere substantially throughout their surfaces. Also, the preferably thickened edge of the pinch affords a structurally interesting possibility of attachment for the relevant current-supply member. To mount the lamp in a suitable holder, it is possible for the lamp to be 'lixed in position in this holder by means of its pinch and/or by means of parts of the current-supply members which extend laterally of the pinch.

In one advantageous embodiment of a light source according to the invention, the part of a current-supply member which extends at the side of the pinch comprises two relatively perpendicular limbs. One limb extends along an edge of the pinch equally directed with -the axis of the lamp and is connected to the IIJ-shaped attachment profile present on the current-supply member; and the other limb extends approximately along -the boundary surface of the pinch at right angles to the axis of the lamp, and carries the area at which the current-supply c ICC wire emerging from the pinch is attached to the currentsupply member. Proceeding in this way it is possible for the relevant current-supply wire to be secured to the current-supply member without being bent, a large cooling surface being present at a small distance from the pinch which is in excellent heat-conductive contact with the pinch substantially without heat-resistance.

In another embodiment of a light source according to the invention a current-supply member extending at the side of the pinch is clamped in position on more than one of the edges of this pinch which are equally directed with the axis of the lamp. In this way a suitable solution is found for an electrical light source in which two or more current-supply wires are led to the exterior through the same pinch. In this case again a large por-tion of the pinch remains capable of radiating its heat freely to the exterior. In this embodiment of the lamp according to the invention, there is no need for a particular insulating body between lthe two metal current-supply members, as is sometimes the case with the usual construction of standard lamps, motorcar lamps, miniature lamps or the like. In the lamp according to the invention the pinch undertakes the function of this particular body of insulating material.

A lamp according to the invention usually has a flat pinch which thus has two edges on which current-supply members of the kind referred to may be fitted. However, the structure according to the invention is also 'applicable if the pinch has a cross-section which is, for example, approximately triangular or quadrangular. Such a current-supply member may then be secured, if desired, to each of the peripheral parts which may be thickened.

In another embodiment of the invention the surface of one limb of a current-supply member is rotated with respect to the surface of the other limb of this currentsupply member. Such an embodiment may be useful, for example, if only a small free space in the transverse direction is available in the holder in which the light source must be placed.

The current-supply member may be made of sheet metal, for example by punching, it being possible to obtain the U-shaped profile by securing a strip of the desired transverse prole against a peripheral part of the resulting metal product, for example by welding, riveting or soldering. The two limbs together will usually form approximately the shape of an L, but it is also possible to choose the shape of a T.

In order that the invention may be readily carried into effect, it will now be described, by way of example, with reference to the accompanying diagrammatic drawings, in which:

FIG. 1 is a side View of a iirst embodiment of the lamp according to the invention;

FIG. 2 is another side vie'w thereof;

FIG. 3 is a sectional View of the pinch portion of the lamp of FIG. 1, together with the current-supply members arranged on it, taken on the plane III- III of FIG. l;

FIG. 4 is a sectional view of a pinch of another ernbodiment of the lamp according to the invention in which the limbs of each current-supply member are rotated with respect to each other, and

FIG. 5 shows an embodiment in which a current-supply member is secured to each of the pinches present at the ends ofthe bulb.

In the lamp of FIGURES l to 3 a filament 11 supported by two supporting wires 12 and 13 is arranged within a bulb 10 of quartz glass. The ends of the supporting Wires 12 and 13 are included in a flat pinch 14 and connected to current-supply wires 17 and 18 through the intermediary of molybdenum foils 15 and 16. The ends of the current-supply wires 17 and 18 project from a 3 boundary surface 19 of the pinch, which is at right angles to the axis A-A of the lamp.

Peripheral parts 20 and 21 of the pinch, which in this example extend in parallel with the axis A-A of the lamp, are made thicker. Current-supply members 22 and 23 respectively are clamped in position on each of said peripheral parts by means of U-shaped profiles the limbs of which are indicated by 23a, 23b and 24a, 24b respectively. So there is an excellent heat-conductive contact between said current-supply members and the pinch of the lamp.

Each of the current-supply members 22 and 23 comprises two relatively perpendicular limbs, 24, 25 and 26, 27 respectively, of which the limbs 24 and 26 are connected to the U-shaped profiles 23a, 23b and 24a, 24h, respectively, and of which the limbs 25 and 27 carry areas 28 and 29 at which the current-supply Wires 17 and 18 are secured to the current-supply members 22 and 23 respectively.

In this construction a considerable part of the pinch remains clear of the external current-supply members, so that this part of the pinch can give up its heat freely by radiation. The limbs 24 and 25 of the current-supply member 22 are co-planar, which is also true for the limbs 26 and 27 of the current-supply member 23. The outer current-supply members 22 and 23 have, for example, several apertures and recesses 30, 31 and 32, which serve to bring the lamp, by means of pins present in a holder, into the' prescribed position relative to optical means co-acting with the lamp.

In the embodiment of FIG. 4, limbs 33 and 34 of current-supply members 35 and 36, respectively, are rotated by 90 relative to the positions of the other limbs of said current-supply members. In this case again the limbs 33 and 34 project at the side of a pinch 37. The other limbs of the current-supply members 35 and 36, which are likewise located at the side of said pinch, are not visible'in FIG. 4 since, similarly as in FIG. 3, they are located under the sectional view of the pinch.

In the embodiment of the lamp according to the invention as shown in FIG. 5, a filament 40 is stretched in the direction of length of a bulb 41 made of quartz glass having at pinches 42 and 43 at its ends. In this example against, supporting wires 44 and 45 are connected to external current-supply wires 48 and 49 respectively through the intermediary of metal foils 46 and 47, respectively, embedded in the pinches. Each of the pinches 42 and 43 has two thicker peripheral parts 50 and 52 respectively, current-supply members 54 and 55 respectively being secured similarly as described with reference t0 FIG. 1, to the thicker peripheral parts which are located under the plane of the drawing. One of the limbs of the current-supply members 54 and 55 respectively, that is to say the limbs 56 and 57 respectively, are connected t0 U-shaped profiles 58 and 59 respectively. The other limbs 60 and 61 respectively, which are at right angles to the first limbs, extend approximately along the end surfaces 62 and 63, respectively, of the relevant pinch which are at right angles to the axis'B-B of the lamp. The latter limbs carry areas 64 and 65 respectively at which the locally available current-supply wires 48 and 49, respectively, are secured to the current-supply members 44 and 55 respectively.

What is claimed is:

1. In an electric lamp including a bulb with a filament therein, a base at one end of the bulb comprising: (a) a pinched and sealed part of the bulb defining in crosssection an elongated central part having length and thickness and ends which are thicker than the central part, (b) two spaced current wires, each of which is disposed in the base, has one end electrically connected to the filament, and has the other end extending outward from the base, and (c) two metal current-supply members, each defining in cross-section a generally U-shaped clamp which engages in heat-conductive contact only a thickened end part 0f the base, thereby leaving exposed the central part for radiating heat directly to the atmosphere, and each being electrically connected to one of said adjacent current wires.

2. A lamp as defined in claim 1 wherein at least one of the current-supply members further comprises an extended portion forming a cooling fin for additional radiation of heat from the lamp.

3. A lamp as defined in claim 2 wherein the extended portion of the current-supply member is in a plane generally transvers to the longitudinal axis of the rectangular base part of the lamp.

4. A lamp as defined in claim 1 wherein said base has av generally rectangular shape in cross-section, and the lamp further comprises: (a) two support wires extending from said base into the bulb and supporting the filament connected between them, and (b) two molybdenum foils disposed in the base, each interconnecting one support wire and one current wire.

References Cited UNITED STATES PATENTS 2,187,736 1/1940 Germer 313-25 2,228,342 1/1941 Claude 313-318 X 2,705,310 3/1955 Hodge 313-318 X 2,892,113 6/1959 Germer 313-42 2,921,221 1/1960 Whitenack 313-318 X 2,930,920 3/1960 Bird 313-318 X 3,320,466 5/1967 Ayres et al. 313-318 3,349,277 10/1967 Terhoeve 313-318 3,360,765 12/1967 Strange et al 313-318 X FOREIGN PATENTS 1,380,283 10/1964 France.

I OHN W. HUCKERT, Primary Examiner.

A. J. JAMES, Assistant Examiner.

U.S. Cl. X.R. 

